Long time lurker, first time poster here.
I've been using JtR and Hashcat for a while, but the current task is stumping me.

I have an Ethereum wallet, V3 scrypt 262144*8*1. The one which is impossible to get going with a gpu.
It is my only option to result to using CPUs.

I have three rigs that I used in the past for other hashes, but this one seems very slow.
Rig 1 AMDFX8320 8 core 3.5 - does 6 H/s
Rig 2 I7 6700k 4 core 4.0 ghz - does 15 H/s
Rig 3 I5 750 2.67 ghz - 4 H/s

I'm looking to maximize the hashrate per watt and $$
Which CPU can outperform the i76700k or possibly any other setup that is still not going to break the bank ?